System for characterizing manual welding operations

ABSTRACT

A system for characterizing manual welding exercises and providing valuable training to welders that includes components for generating, capturing, and processing data. The data generating component further includes a fixture, workpiece, at least one calibration devices each having at least two point markers integral therewith, and a welding tool. The data capturing component further includes an imaging system for capturing images of the point markers and the data processing component is operative to receive information from the data capturing component and perform various position and orientation calculations.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is being filed as a continuation application ofU.S. patent application Ser. No. 16/021,576 filed on Jun. 28, 2018,which is a divisional application of U.S. patent application Ser. No.15/077,532 filed on Mar. 22, 2016, now U.S. Pat. No. 10,068,495 issuedon Sep. 4, 2018, which is a continuation of both U.S. patent applicationSer. No. 14/293,700 filed on Jun. 2, 2014, now U.S. Pat. No. 9,773,429issued on Sep. 26, 2017, and U.S. patent application Ser. No. 14/293,826filed on Jun. 2, 2014, now abandoned, each of which is acontinuation-in-part of U.S. patent application Ser. No. 13/543,240filed on Jul. 6, 2012, now U.S. Pat. No. 9,221,117 issued on Dec. 29,2015, which is a continuation-in-part of both U.S. patent applicationSer. No. 12/966,570 filed on Dec. 13, 2010, now U.S. Pat. No. 9,230,449issued on Jan. 5, 2016 (which itself is a continuation-in-part of U.S.patent application Ser. No. 12/499,687 filed on Jul. 8, 2009, nowabandoned) and U.S. patent application Ser. No. 12/499,687 filed on Jul.8, 2009, now abandoned, the entire disclosures of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The described invention relates in general to a system forcharacterizing manual welding operations, and more specifically to asystem for providing useful information to a welding trainee bycapturing, processing, and presenting in a viewable format, datagenerated by the welding trainee in manually executing an actual weld inreal time.

The manufacturing industry's desire for efficient and economical weldertraining has been a well documented topic over the past decade as therealization of a severe shortage of skilled welders is becomingalarmingly evident in today's factories, shipyards, and constructionsites. A rapidly retiring workforce combined with the slow pace oftraditional instructor-based welder training has been the impetus forthe development of more effective training technologies. Innovationswhich allow for the accelerated training of the manual dexterity skillsspecific to welding, along with the expeditious indoctrination of arcwelding fundamentals are becoming a necessity. The characterization andtraining system disclosed herein addresses this vital need for improvedwelder training and enables the monitoring of manual welding processesto ensure the processes are within permissible limits necessary to meetindustry-wide quality requirements. To date, the majority of weldingprocesses are performed manually, yet the field is lacking practicalcommercially available tools to track the performance of these manualprocesses. Thus, there is an ongoing need for an effective system fortraining welders to properly execute various types of welds undervarious conditions.

SUMMARY OF THE INVENTION

The following provides a summary of certain exemplary embodiments of thepresent invention. This summary is not an extensive overview and is notintended to identify key or critical aspects or elements of the presentinvention or to delineate its scope.

In accordance with one aspect of the present invention, a system forcharacterizing manual and/or semiautomatic welding operations andexercises is provided. This system includes a data generating component;a data capturing component; and a data processing component. The datagenerating component further includes a fixture, wherein the geometriccharacteristics of the fixture are predetermined; a workpiece adapted tobe mounted on the fixture, wherein the workpiece includes at least onejoint to be welded, and wherein the vector extending along the joint tobe welded defines an operation path; at least one calibration device,wherein each calibration device further includes at least two pointmarkers integral therewith, and wherein the geometric relationshipbetween the point markers and the operation path is predetermined; and awelding tool, wherein the welding tool is operative to form a weld atthe joint to be welded, wherein the welding tool defines a tool pointand a tool vector, and wherein the welding tool further includes atarget attached to the welding tool, wherein the target further includesa plurality of point markers mounted thereon in a predetermined pattern,and wherein the predetermined pattern of point markers is operative todefine a rigid body. The data capturing component further includes animaging system for capturing images of the point markers. The dataprocessing component is operative to receive information from the datacapturing component and then calculate the position and orientation ofthe operation path relative to the three-dimensional space viewable bythe imaging system; the position of the tool point and orientation ofthe tool vector relative to the rigid body; and the position of the toolpoint and orientation of the tool vector relative to the operation path.

In accordance with another aspect of the present invention, a system forcharacterizing manual and/or semiautomatic welding operations andexercises is also provided. This system includes a data generatingcomponent; a data capturing component; and a data processing component.The data generating component further includes a fixture, wherein thegeometric characteristics of the fixture are predetermined; a workpieceadapted to be mounted on the fixture, wherein the workpiece includes atleast one joint to be welded, and wherein the vector extending along thejoint to be welded defines an operation path; at least one calibrationdevice, wherein each calibration device further includes at least twopoint markers integral therewith, and wherein the geometric relationshipbetween the point markers and the operation path is predetermined; and awelding tool, wherein the welding tool is operative to form a weld atthe joint to be welded, wherein the welding tool defines a tool pointand a tool vector, and wherein the welding tool further includes atarget attached to the welding tool, wherein the target further includesa plurality of point markers mounted thereon in a predetermined pattern,and wherein the predetermined pattern of point markers is operative todefine a rigid body. The data capturing component further includes animaging system for capturing images of the point markers and the imagingsystem further includes a plurality of digital cameras. At least oneband-pass filter is incorporated into the optical sequence for each ofthe plurality of digital cameras for permitting light from only thewavelengths which are reflected or emitted from the point markers forimproving image signal-to-noise ratio. The data processing component isoperative to receive information from the data capturing component andthen calculate the position and orientation of the operation pathrelative to the three-dimensional space viewable by the imaging system;the position of the tool point and orientation of the tool vectorrelative to the rigid body; and the position of the tool point andorientation of the tool vector relative to the operation path.

Additional features and aspects of the present invention will becomeapparent to those of ordinary skill in the art upon reading andunderstanding the following detailed description of the exemplaryembodiments. As will be appreciated by the skilled artisan, furtherembodiments of the invention are possible without departing from thescope and spirit of the invention. Accordingly, the drawings andassociated descriptions are to be regarded as illustrative and notrestrictive in nature.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a partof the specification, schematically illustrate one or more exemplaryembodiments of the invention and, together with the general descriptiongiven above and detailed description given below, serve to explain theprinciples of the invention, and wherein:

FIG. 1 is a flow chart illustrating the flow of information through thedata processing and visualization component of an exemplary embodimentof the present invention;

FIG. 2 provides an isometric view of a portable or semi-portable systemfor characterizing manual welding operations, in accordance with anexemplary embodiment of the present invention;

FIG. 3 provides an isometric view of the flat assembly of the system ofFIG. 2;

FIG. 4 provides an isometric view of the horizontal assembly of thesystem of FIG. 2;

FIG. 5 provides an isometric view of the vertical assembly of the systemof FIG. 2;

FIG. 6 illustrates the placement of two point markers on the flatassembly of FIG. 2;

FIG. 7 illustrates an exemplary workpiece operation path;

FIG. 8 illustrates the placement of two active or passive point markerson an exemplary workpiece for determining a workpiece operation path;

FIG. 9 is a flowchart detailing the process steps involved in anexemplary embodiment of a first calibration component of the presentinvention;

FIG. 10 illustrates the welding tool of an exemplary embodiment of thisinvention showing the placement of the point markers used to define therigid body;

FIG. 11 illustrates the welding tool of an exemplary embodiment of thisinvention showing the placement of the point markers used to define thetool vector and the rigid body; and

FIG. 12 is a flowchart detailing the process steps involved in anexemplary embodiment of a second calibration component of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the present invention are now described withreference to the Figures. Reference numerals are used throughout thedetailed description to refer to the various elements and structures. Inother instances, well-known structures and devices are shown in blockdiagram form for purposes of simplifying the description. Although thefollowing detailed description contains many specifics for the purposesof illustration, a person of ordinary skill in the art will appreciatethat many variations and alterations to the following details are withinthe scope of the invention. Accordingly, the following embodiments ofthe invention are set forth without any loss of generality to, andwithout imposing limitations upon, the claimed invention.

The present invention relates to an advanced system for observing andcharacterizing manual welding exercises and operations. This system isparticularly useful for welding instruction and welder training thatprovides an affordable tool for measuring manual welding technique andcomparing that technique with established procedures. The trainingapplications of this invention include: (i) screening applicant skilllevels; (ii) assessing trainee progress over time; (iii) providingreal-time coaching to reduce training time and costs; and (iv)periodically re-testing welder skill levels with quantifiable results.Processing monitoring and quality control applications include: (i)identification of deviations from preferred conditions in real time;(ii) documenting and tracking compliance with procedures over time;(iii) capturing in-process data for statistical process control purposes(e.g., heat input measurements); and (iv) identifying welders needingadditional training. The system of the present invention provides theunique benefit of enabling the determination of compliance with variousaccepted welding procedures.

The present invention, in various exemplary embodiments, measures torchmotion and gathers process data during welding exercises using a singleor multiple camera tracking system based on point cloud image analysis.This invention is applicable to a wide range of processes including, butnot necessarily limited to, GMAW, FCAW, SMAW, GTAW, and cutting. Theinvention is expandable to a range of work-piece configurations,including large sizes, various joint type, pipe, plate, and complexshapes. Measured parameters include work angle, travel angle, toolstandoff, travel speed, bead placement, weave, voltage, current, wirefeed speed, and arc length. The training component of the presentinvention may be pre-populated with specific welding procedures or itmay be customized by an instructor. Data is automatically saved andrecorded, a post-weld analysis scores performance, and progress istracked over time. This system may be used throughout an entire weldingtraining program and may include both in-helmet and on-screen feedback.With reference now to the Figures, one or more specific embodiments ofthis invention shall be described in greater detail.

As shown in FIG. 1, in an exemplary embodiment of the present invention,the basic flow of information through data generating component 100,data capturing component 200, and data processing (and visualization)component 300 of weld characterization system 10 occurs in six basicsteps: (1) image capture 110; (2) image processing 112; (3) input of arcweld data 210, such as known or preferred weld parameters; (4) dataprocessing 212; (5) data storage 214; and (5) data display 310. Imagecapture step 110 includes capturing images of target 98 (which typicallyincludes at least two point markers located in a fixed geometricrelationship to one another) with one or more off-the shelfhigh-speed-vision cameras, where the output aspect typically includescreating of an image file at over 100 frames per second. The inputaspect of image processing step 112 includes frame-by-frame point cloudanalysis of a rigid body that includes three or more point markets(i.e., the calibrated target). Upon recognition of a known rigid body,position and orientation are calculated relative to the camera originand the “trained” rigid body orientation. Capturing and comparing theimages from two or more cameras allows for a substantially accuratedetermination of the rigid body position and orientation inthree-dimensional space. Images are typically processed at a rate ofmore than 10 times per second. The output aspect of image processingstep 112 includes creation of a data array that includes x-axis, y-axis,and z-axis positional data and roll, pitch, and yaw orientation data, aswell as time stamps and software flags. The text file may be streamed orsent at a desired frequency. The input aspect of data processing step212 includes raw positional and orientation data typically requested ata predetermined rate, while the output aspect includes transforming thisraw data into useful welding parameters with algorithms specific to aselected process and joint type. The input aspect of data storage step214 includes storing welding trial data as a *.dat file, while theoutput aspect includes saving the data for review and tracking, savingthe date for review on a monitor at a later time, and/or reviewing theprogress of the student at a later time. Student progress may includetotal practice time, total arc time, total arc starts, and individualparameter-specific performance over time. The input aspect of datadisplay step 310 includes welding trial data that further includes workangle, travel angle, tool standoff, travel speed, bead placement, weave,voltage, current, wire-feed speed, while the output aspect involves datathat may viewed on a monitor, in-helmet display, heads-up display, orcombinations thereof, wherein parameters are plotted on a time-basedaxis and compared to upper and lower thresholds or preferred variations,such as those trained by recording the motions of an expert welder.Current and voltage may be measured in conjunction with travel speed todetermine heat input and the welding process parameters may be used toestimate arc length. Position data may be transformed into weld startposition, weld stop position, weld length, weld sequence, weldingprogression, or combinations thereof and current and voltage may bemeasured in conjunction with travel speed to determine heat input.

FIGS. 2-5 provide illustrative views of weld characterization system 10in accordance with an exemplary embodiment the present invention. Asshown in FIG. 2, portable training stand 20 includes a substantiallyflat base 22 for contact with a floor or other horizontal substrate,rigid vertical support column 24, camera or imaging device support 26,and rack and pinion assembly 31 for adjusting the height of imagingdevice support 26. In most embodiments, weld characterization system 10is intended to be portable or at least moveable from one location toanother, therefore the overall footprint of base 22 is relatively smallto permit maximum flexibility with regard to installation and use. Asshown in FIG. 2-6, weld characterization system 10 may be used fortraining exercises that include flat, horizontally or verticallyoriented workpieces. In the exemplary embodiments shown in the Figures,training stand 20 is depicted as a unitary or integrated structure thatis capable of supporting the other components of system. In otherembodiments, stand 20 is absent and the various components of the systemare supported by whatever suitable structural or supportive means may beavailable. Thus, within the context of this invention, “stand” 20 isdefined as any single structure or, alternately, multiple structuresthat are capable of supporting the components of weld characterizationsystem 10.

With to FIGS. 2-3, certain welding exercises will utilize a flatassembly 30, which is slidably attached to vertical support column 24 bycollar 34, which slides upward or downward on support column 24. Collar34 is further supported on column 24 by rack and pinion 31, whichincludes shaft 32 for moving rack and pinion assembly 31 upward ordownward on support column 24. Flat assembly 30 includes trainingplatform 38, which is supported by one or more brackets (not visible).In some embodiments, a shield 42 is attached to training platform 38 forprotecting the surface of support column 24 from heat damage. Trainingplatform 38 further includes at least one clamp 44 for securing weldposition-specific fixture/jig 46 to the surface of the trainingplatform. The structural configuration or general characteristics ofweld position-specific jig 46 are variable based on the type of weldprocess that is the subject of a particular welding exercise, and inFIGS. 2-3, fixture 46 is configured for a fillet weld exercise. In theexemplary embodiment shown in FIGS. 2-3, first 48 and second 50structural components of weld position-specific fixture 46 are set atright angles to one another. Position-specific fixture 46 may includeone or more pegs 47 for facilitating proper placement of a weld couponon the fixture. The characteristics of any weld coupon (workpiece) 54used with system 10 are variable based on the type of manual weldingprocess that is the subject of a particular training exercise and in theexemplary embodiment shown in the FIGS. 7-8, first 56 and second 58portions of weld coupon 54 are also set at right angles to one another.With reference to FIGS. 4-5, certain other welding exercises willutilize a horizontal assembly 30 (see FIG. 4) or a vertical assembly 30(see FIG. 5). In FIG. 4, horizontal assembly 30 supports butt fixture46, which holds workpiece 54 in the proper position for a butt weldexercise. In FIG. 5, vertical assembly 30 supports vertical fixture 46,which holds workpiece 54 in the proper position for a lap weld exercise.

Data processing component 300 of the present invention typicallyincludes at least one computer for receiving and analyzing informationcaptured by the data capturing component 200, which itself includes atleast one digital camera contained in a protective housing. Duringoperation of weld characterization system 10, this computer is typicallyrunning software that includes a training regimen module, an imageprocessing and rigid body analysis module, and a data processing module.The training regimen module includes a variety of weld types and aseries of acceptable welding process parameters associated with creatingeach weld type. Any number of known or AWS weld joint types and theacceptable parameters associated with these weld joint types may beincluded in the training regimen module, which is accessed andconfigured by a course instructor prior to the beginning of a trainingexercise. The weld process and/or type selected by the instructordetermine which weld process-specific fixture, calibration device, andweld coupon are used for any given training exercise. The objectrecognition module is operative to train the system to recognize a knownrigid body target 98 (which includes two or more point markers) and forthen to use target 98 to calculate positional and orientation data forwelding gun 90 as an actual manual weld is completed by a trainee. Thedata processing module compares the information in the training regimenmodule to the information processed by the object recognition module andoutputs the comparative data to a display device such as a monitor orhead-up display. The monitor allows the trainee to visualize theprocessed data in real time and the visualized data is operative toprovide the trainee with useful feedback regarding the characteristicsand quality of the weld. The visual interface of weld characterizationsystem 10 may include a variety of features related to the input ofinformation, login, setup, calibration, practice, analysis, and progresstracking. The analysis screen typically displays the welding parametersfound in the training regimen module, including (but not limited to)work angle, travel angle, tool standoff, travel speed, bead placement,weave, voltage, current, wire-feed speed, and arc length. Multipledisplay variations are possible with the present invention.

In most, if not all instances, weld characterization system 10 will besubjected to a series of calibration steps/processes prior to use. Someof the aspects of the system calibration will typically be performed bythe manufacturer of system 10 prior to delivery to a customer and otheraspects of the system calibration will typically be performed by theuser of weld characterization system 10 prior to any welding trainingexercises. System calibration typically involves two related andintegral calibration processes: (i) determining the three-dimensionalposition and orientation of the operation path to be created on aworkpiece for each joint/position combination to be used in variouswelding training exercises; and (ii) determining the three-dimensionalposition and orientation of the welding tool by calculating therelationship between a plurality of reflective (passive) or lightemitting (active) point markers located on target 98 and at least twokey points represented by point markers located on the welding tool 90.

The first calibration aspect of this invention typically involves thecalibration of the welding operation with respect to the globalcoordinate system, i.e., relative to the other structural components ofweld characterization system 10 and the three-dimensional space occupiedthereby. Prior to tracking/characterizing a manual welding exercise, theglobal coordinates of each desired operation path (i.e., vector) on anygiven workpiece will be determined. In most embodiments, this is afactory-executed calibration process that will include correspondingconfiguration files stored on data processing component 200. To obtainthe desired vectors, a calibration device containing active or passivemarkers may be inserted on at least two locating markers in each of thethree possible platform positions (i.e., flat, horizontal, andvertical). FIGS. 6-8 illustrate this calibration step in one possibleplatform position. Joint-specific fixture 46 includes first and secondstructural components 48 (horizontal) and 50 (vertical), respectively.Weld coupon or workpiece 54 includes first and second portions 56(horizontal) and 58 (vertical), respectively. Workpiece operation path59 extends from point X to point Y and is shown in broken line in FIG.7. Locating point markers 530 and 532 are placed as shown in FIG. 6 (andFIG. 8) and the location of each marker is obtained using data capturingcomponent 100, which in this embodiment utilizes Optitrack TrackingTools (NaturalPoint, Inc.) or a similar commercially available orproprietary hardware/software system that provides three-dimensionalmarker and six degrees of freedom object motion tracking in real time.Such technologies typically utilize reflective and/or light emittingpoint markers arranged in predetermined patterns to create point cloudsthat are interpreted by system imaging hardware and system software as“rigid bodies”, although other suitable methodologies are compatiblewith this invention.

In the calibration process represented by the flowchart of FIG. 9, table38 is fixed into position i (0,1,2) at step 280; a calibration device isplaced on locating pins at step 282; all marker positions are capturedat step 284; coordinates for the locator positions are calculated atstep 286; coordinates for the fillet operation path are calculated atstep 288 and stored at 290; coordinates for the lap operation path arecalculated at step 292 and stored at 294; and coordinates for the grooveoperation path are calculated at step 296 and stored at 298. Allcoordinates are calculated relative to the three dimensional spaceviewable by data capturing component 200.

In one embodiment of this invention, the position and orientation of thework-piece is calibrated through the application of two or more passiveor active point markers to a calibration device that is placed at aknown translational and rotational offset to a fixture that holds thework-piece at a known translational and rotational offset. In anotherembodiment of this invention, the position and orientation of thework-piece is calibrated through the application of two or more passiveor active point markers to a fixture that holds the work-piece at aknown translational and rotational offset. In still other embodiments,the workpiece is non-linear, and the position and orientation thereofmay be mapped using a calibration tool with two or more passive oractive point markers and stored for later use. The position andorientation of the work-piece operation path may undergo apre-determined translational and rotational offset from its originalcalibration plane based on the sequence steps in the overall workoperation.

Important tool manipulation parameters such as position, orientation,velocity, acceleration, and spatial relationship to the work-pieceoperation path may be determined from the analysis of consecutive toolpositions and orientations over time and the various work-pieceoperation paths described above. Tool manipulation parameters may becompared with pre-determined preferred values to determine deviationsfrom known and preferred procedures. Tool manipulation parameters mayalso combined with other manufacturing process parameters to determinedeviations from preferred procedures and these deviations may be usedfor assessing skill level, providing feedback for training, assessingprogress toward a skill goal, or for quality control purposes. Recordedmotion parameters relative to the workpiece operation path may beaggregated from multiple operations for statistical process controlpurposes. Deviations from preferred procedures may be aggregated frommultiple operations for statistical process control purposes. Importanttool manipulation parameters and tool positions and orientations withrespect to the workpiece operation path may also be recorded forestablishing a signature of an experienced operator's motions to be usedas a baseline for assessing compliance with preferred procedures.

The second calibration aspect typically involves the calibration ofwelding tool 90 with respect to target 98. “Welding” tool 90 istypically a welding torch or gun or SMAW electrode holder, but may alsobe any number of other implements including a soldering iron, cuttingtorch, forming tool, material removal tool, paint gun, or wrench. Withreference to FIGS. 10-11, welding gun/tool 90 includes tool point 91,nozzle 92, body 94, trigger 96, and target 98. Tool calibration device93, which includes two integrated active or passive point markers in theA and B positions (see FIG. 11) is attached to or inserted into nozzle92. A rigid body point cloud (i.e., a “rigid body”) is constructed byattaching active or passive point markers 502, 504, and 506 (andadditional point markers) to the upper surface of target 98 (otherplacements are possible). Target 98 may include a power input if thepoint markers used are active and require a power source. Data capturingcomponent 200 uses Optitrack Tracking Tools (NaturalPoint, Inc.) orsimilar hardware/software to locate the rigid body and point markers 522(A) and 520 (B), which represent the location of tool vector 524. Thesepositions can be extracted from the software of system 10 and therelationship between point markers A and B and the rigid body can becalculated.

In the calibration process represented by the flowchart of FIG. 12, weldnozzle 92 and the contact tube are removed at step 250; the calibrationdevice is inserted into body 94 at step 252; weld tool 90 is placed inthe working envelope and rigid body 500 (designated as “S” in FIG. 11)and point markers A and B are captured by data capturing component 100;the relationships between A and S and B and S are calculated at step256; relationship data for As is stored at 258; and relationship datafor Bs is stored at 260.

In one embodiment of this invention, calibration of the tool point andtool vector is performed through the application of two or more passiveor active point markers to the calibration device at locations along thetool vector with a known offset to the tool point. In anotherembodiment, calibration of the tool point and tool vector is performedby inserting the tool into a calibration block of known position andorientation relative to the work-piece. With regard to the rigid bodydefined by the point markers (e.g., 502, 504, 506), in one embodiment,the passive or active point markers are affixed to the tool in in amulti-faceted manner so that a wide range of rotation and orientationchanges can be accommodated within the field of view of the imagingsystem. In another embodiment, the passive or active point markers areaffixed to the tool in a spherical manner so that a wide range ofrotation and orientation changes can be accommodated within the field ofview of the imaging system. In still another embodiment, the passive oractive point markers are affixed to the tool in a ring shape so that awide range of rotation and orientation changes can be accommodatedwithin the field of view of the imaging system.

Numerous additional useful features may be incorporated into the presentinvention. For example, for purposes of image filtering, band-pass orhigh-pass filters may be incorporated into the optical sequence for eachof the plurality of digital cameras in data capturing component 200 forpermitting light from only the wavelengths which are reflected oremitted from the point markers to improve image signal-to-noise ratio.Spurious data may be rejected by analyzing only image informationobtained from within a dynamic region of interest having a limitedoffset from a previously known rigid-body locality. This dynamic regionof interest may be incorporated into or otherwise predefined (i.e.,preprogrammed as a box or region of width x and height y and centered onknown positions of target 98) within the field of view of each digitalcamera such that image information is only processed from thispredefined region. The region of interest will change as the rigid bodymoves and is therefore based on previously known locations of the rigidbody. This approach allows the imaging system to view only pixels withinthe dynamic region of interest when searching for point markers whiledisregarding or blocking pixels in the larger image frame that are notincluded in the dynamic region of interest. Decreased processing time isa benefit of this aspect of the invention.

While the present invention has been illustrated by the description ofexemplary embodiments thereof, and while the embodiments have beendescribed in certain detail, it is not the intention of the Applicant torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to any of the specific details, representativedevices and methods, and/or illustrative examples shown and described.Accordingly, departures may be made from such details without departingfrom the spirit or scope of the applicant's general inventive concept.

The invention claimed is:
 1. A method of characterizing a manual weldingoperation, the method comprising: providing a plurality of weldingparameters for a manual welding operation; providing a workpiece to bewelded by the manual welding operation; providing a calibration tool,the calibration tool including a plurality of first point markers;providing a welding tool, the welding tool including a plurality ofsecond point markers arranged in a predetermined pattern; placing theworkpiece on a weld platform; placing the calibration tool on the weldplatform; capturing at least one image of the first point markers of thecalibration tool on the weld platform; processing the at least one imageof the first point markers on the calibration tool to determine aposition and orientation of an operational path for the manual weldingoperation based on at least one of the welding parameters; manuallywelding the workpiece with the welding tool; capturing a plurality ofimages of the second point markers on the welding tool during the manualwelding operation; processing the plurality of images of the secondpoint markers on the welding tool to determine a position andorientation of the welding tool; and determining a plurality ofcharacteristics of the manual welding operation based on the positionand orientation of the operational path and the position and orientationof the welding tool, wherein the characteristics are selected from thegroup consisting of: a welding tool work angle, a welding tool travelangle, a welding tool travel speed, a bead placement, and a welding toolstandoff distance.
 2. The method of claim 1, wherein the weld platformincludes a plurality of pins for removably attaching the calibrationtool to the weld platform.
 3. The method of claim 1, wherein the weldplatform includes a plurality of clamps to secure the workpiece to theweld platform.
 4. The method of claim 1, wherein the weld platform isconnected to a stand.
 5. The method of claim 4, further comprisingdisplaying the characteristics on a monitor, wherein the monitor iscoupled to the stand.
 6. The method of claim 4, wherein the standincludes a vertical support.
 7. The method of claim 6, wherein an angleof the weld platform relative to the vertical support is adjustable. 8.The method of claim 6, wherein a height of the weld platform relative tothe vertical support is adjustable.
 9. The method of claim 4, wherein anoptical camera system is coupled to the stand, the optical camera systemcomprising a plurality of spatially-separated cameras, and wherein theoptical camera system is operable to capture images containing at leastone of the first point markers and the second point markers.
 10. Themethod of claim 1, wherein the calibration tool is in physical contactwith the workpiece on the weld platform.
 11. The method of claim 1,wherein the second point markers are active point markers.
 12. Themethod of claim 1, wherein the second point markers are light-emittingpoint markers.
 13. The method of claim 1, further comprising comparingeach of the welding tool work angle, the welding tool travel angle, thewelding tool travel speed, the bead placement, and the welding toolstandoff distance to a corresponding predetermined lower threshold valueand a corresponding predetermined upper threshold value.
 14. The methodof claim 13, further comprising calculating a performance score for themanual welding operation based on the comparison of at least one of thewelding tool work angle, the welding tool travel angle, the welding tooltravel speed, the bead placement, and the welding tool standoff distanceto the corresponding predetermined lower threshold value and thecorresponding predetermined upper threshold value.
 15. The method ofclaim 1, further comprising comparing each of the welding tool workangle, the welding tool travel angle, the welding tool travel speed, thebead placement, and the welding tool standoff distance to acorresponding predetermined preferred value.
 16. The method of claim 15,further comprising calculating a performance score for the manualwelding operation based on the comparison of at least one of the weldingtool work angle, the welding tool travel angle, the welding tool travelspeed, the bead placement, and the welding tool standoff distance to thecorresponding predetermined preferred value.
 17. The method of claim 1,wherein the welding tool includes more than three of the second pointmarkers, and wherein the predetermined pattern has no axis of symmetry.